def anonymize(cls, user, ldap_attrs, **kwargs):
    # type: (User, Dict[AnyStr, Any], **Any) -> Dict[AnyStr, AnyStr]
    """
    Change values of function arguments to anonymize/pseudonymize user if
    UCRV asm/attributes/<staff/student>/anonymize is true. Will return
    unchanged function arguments otherwise.
    :param User user: user object
    :param dict ldap_attrs: dictionary with the users LDAP attributes
    :return: dictionary with [modified] function arguments
    :rtype: dict
    :raises NotImplementedError: if cls.ucr_anonymize_key_base is unset
    """
    ucr = get_ucr()
    if ucr.is_true(cls.ucr_anonymize_key_base):
        for k, v in cls.anonymize_mapping().items():
            if v and v.startswith('%'):
                attr = v[1:].strip()
                try:
                    v = ldap_attrs[attr][0]
                except KeyError:
                    raise ValueError('Attribute {!r} not found in LDAP object of {}.'.format(attr, user))
                except IndexError:
                    raise ValueError('Attribute {!r} empty in LDAP object of {}.'.format(attr, user))
            kwargs[k] = v
    return kwargs